Monumental, the Amsterdam-based construction robotics company, has raised a $32 million Series B led by Khosla Ventures, with participation from existing investors Plural and Hummingbird, according to Tech.eu. The company builds compact, electric, self-driving robots that show up on a job site and lay brick and block walls — and it is using the new money to bring them to the United States.
The raise follows a $25 million round in February 2024, Fortune reports, and it lands at a moment when capital is flooding into construction robotics on the premise that the industry’s labor shortage is permanent and structural. What makes Monumental worth a closer look than the average robot-on-a-jobsite story is less the hardware than the business model wrapped around it.
It doesn’t sell robots. It sells walls.
Most construction-robotics companies are, in the end, equipment companies. They build a machine and sell or lease it to a contractor, who then has to buy it, finance it, train people on it, maintain it, and figure out how to keep it busy enough to justify the capital. That is a hard sell into an industry with thin margins and a deep, well-earned skepticism of anything that arrives with a sales deck.
Monumental refuses that model outright. It operates as an independent subcontractor: it bids for the wall-building scope on a project, sends its own robots and engineers, and gets paid only when the wall is finished. “We’re selling them a wall,” co-founder and CEO Salar al Khafaji told Fortune. Contractors never touch the robots or the software; they buy an outcome, the same way they would from any masonry sub.
It is a deliberately unglamorous framing for a robotics company, and a shrewd one. It strips out the two things contractors hate most about new technology — the capital outlay and the learning curve — and replaces them with a line item they already understand. It also quietly aligns Monumental’s incentives with the customer’s: if the robots are slow or unreliable, that is Monumental’s cost to eat, not the contractor’s.
That model only works if the machines actually perform at volume, and Monumental’s claim is that they now do. The company operates more than 150 robots on live European job sites, according to both Fortune and Tech.eu. Its machines have helped build exterior walls for more than 100 homes across the Netherlands and the UK, along with a school, a community centre, a hotel and sections of canal wall, the company said. Monumental says nearly half of those homes went up in the last three months — the kind of steepening curve investors pay a premium for, because it suggests the model has moved from working to scaling.
The Palantir lineage
Al Khafaji and co-founder Sebastiaan Visser are not first-time founders, and their history is written into how the company operates. The two previously built Silk, a data-visualization company that Palantir acquired in 2016, per Fortune. Monumental leans on the same forward-deployed engineering approach Palantir made famous — putting its own engineers on real job sites, next to the machines and the trades, rather than shipping a finished product over the wall and hoping it survives contact with a construction schedule.
That is a meaningful choice in a sector where the graveyard is full of technically impressive robots that never adapted to the mess of an actual site. Bricklaying in a lab is a solved problem; bricklaying on a rain-slicked site with out-of-tolerance foundations, changing mortar, and a schedule that shifts weekly is not. Monumental’s bet is that the hard part is not the robotics but the integration — and that a team wired to embed engineers on site has an edge on exactly that problem.
It is the same physical-AI thesis drawing capital across the sector, from Gravis Robotics’ work on autonomous heavy equipment to All3’s $25 million seed for legged construction robots and Sitegeist’s concrete-repair robots. Monumental’s wager is that masonry — repetitive, physically punishing, and chronically short of labor — is the wedge where robots can prove their economics before anything more ambitious.
Why the US, and why it is harder than it looks
The labor math is the whole pitch, and al Khafaji frames the shortage as effectively bottomless: “You could have 10,000 robots a day and we would literally have just touched a few percentage points of the shortage,” he told Fortune. Against that backdrop, the company is taking its fleet across the Atlantic this year, targeting Texas, Florida, Virginia and Arizona — states Fortune identifies as combining high building activity with acute labor scarcity.
The US is a harder proving ground than the headline suggests. American residential construction leans heavily on wood framing rather than the brick-and-block Monumental has optimized for in Europe, which narrows the initial addressable market to the specific segments — and the specific states — where masonry is common. The four states named are not an accident: they skew toward block-and-masonry construction and toward the Sun Belt’s building boom. But it means the company is entering the US not as a general-purpose bricklaying service but as a specialist looking for the pockets of the market that resemble the one it already knows.
The outcome-based model also cuts both ways on foreign soil. “We only get paid when the wall is built” is a promise that punishes any gap between demo-day performance and job-site reliability. A robot that stalls in Texas heat, or a crew that cannot get a machine calibrated on an unfamiliar foundation, is Monumental’s problem to absorb — on its own balance sheet, thousands of miles from its engineering base.
What to watch
The signal to track is not the fleet count but the unit economics per completed wall as the company scales into a new continent. Monumental has now shown it can run more than 150 robots and hold a schedule across a hundred-plus European projects. The open question is whether that record travels: whether the same reliability holds on US foundations, in US weather, under US building codes, with a support organization stretched across an ocean.
If it does, the outcome-based model becomes one of the more defensible positions in construction robotics, because it forces Monumental to carry the execution risk that most robotics vendors quietly push onto their customers — and a contractor who can buy a finished wall at a predictable price, with none of the capital or training overhead, has little reason to say no. If it doesn’t, Monumental is the party that finds out first, one unbuilt wall at a time. Khosla’s $32 million is a bet that the company already knows which way that goes.
